Biodiversity

Biodiversity is the variety of life on Earth — the number and variety of species, genes, and ecosystems in a given area. High biodiversity makes ecosystems more stable and resilient, and provides many resources that humans depend on.

A species is endangered when its population has declined so much that it faces a real risk of extinction. The main causes are habitat loss, hunting, pollution, climate change, and invasive species. Conservation efforts work to protect and recover threatened populations.